Engine balancer for a four cylinder in-line internal combustion engine

Abstract

An engine balancer for a four cylinder in-line internal combustion engine. The balancer is mounted centrally under the crankshaft and driven by a drive gear adjacent the nodal point of torsional vibrations on the crankshaft. The balancer is for secondary forces on the engine and the drive reduces feed of torsional vibrations to the engine balancer from the crankshaft.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. An engine balancer on a four cylinder in-line engine comprising, a crankshaft rotatably mounted on an axis of rotation, a plurality of main bearings rotatably supporting said crankshaft, a drive end of said crankshaft for the output drive of said crankshaft, a flywheel firmly fixed to said drive end of said crankshaft defining a nodal point of crankshaft torsional vibrations, a plurality of pistons connected through connecting rods driving said crankshaft, and engine balancer centrally mounted relative to said crankshaft including a pair of counterweights eccentrically mounted on axes of rotation parallel to said crankshaft axis, a balancer drive gear directly connected to said crankshaft adjacent one of the main bearings in the low torsional vibration amplitude area on the flywheel side of said balancer near the flywheel and said nodal point of torsional vibrations, driven gear means on the flywheel side of said balancer driven by said drive gear to thereby essentially eliminate transmission of torsional vibration from said crankshaft to said balancer. 
     
     
       2. An engine balancer on a four cylinder in-line engine as set forth in claim 1 wherein said balancer includes a casing mounting said balancer under said crankshaft. 
     
     
       3. An engine balancer on a four cylinder in-line engine as set forth in claim 1 wherein, said counterweights of said balancer include a clamping structure and screw fastening means for selectively angularly adjusting said counterweights on their respective shafts to adjust the angular position of said counterweights relative to the rotation of said crankshaft. 
     
     
       4. An engine balancer on a four cylinder in-line engine as set forth in claim 1 including five main bearings axially spaced between crank arms on said crankshaft with the fifth main bearing adjacent said flywheel, means fastening said drive gear adjacent said fourth main bearing. 
     
     
       5. An engine balancer on a four cylinder in-line engine as set forth in claim 1 including, five main bearings rotatably supporting said crankshaft with the main bearings positioned intermediate each of four crank arms of said crankshaft and at each end of said crankshaft, means connecting said drive gear adjacent said fifth main bearing. 
     
     
       6. An engine balancer on a four cylinder in-line engine as set forth in claim 1 including means defining a nodal point adjacent said flywheel, means connecting said drive gear on said crankshaft for driving said balancer at the nodule point adjacent said flywheel. 
     
     
       7. An engine balancer on a four cylinder in-line engine as set forth in claim 1 wherein, said crank arms of said crankshaft lie in a common plane. 
     
     
       8. An engine balancer on a four cylinder in-line engine as set forth in claim 1 including, means mounting said balancer on the underside of said crankshaft. 
     
     
       9. An engine balancer on a four cylinder in-line engine as set forth in claim 1 including, five main bearings for rotatably supporting said crankshaft. 
     
     
       10. An engine balancer on a four cylinder in-line engine as set forth in claim 1 including, a driven gear mounted on each shaft fixed to each of said counterweights, needle bearings rotatably supporting each of said shafts for rotation about said axes parallel with said crankshaft axis.